Innate Type 2 Immunity Controls Hair Follicle Commensalism by Demodex Mites

The study investigates the role of innate type 2 immunity in controlling Demodex mite colonization in hair follicles. In mice, group 2 innate lymphoid cells (ILC2s) and interleukin-13 (IL-13) are crucial for preventing mite overgrowth by regulating hair follicle and epithelial proliferation. Without ILC2s and IL-13, increased epithelial proliferation and inflammation occur, leading to hair follicle damage. In humans with rhinophymatous acne rosacea, a condition linked to Demodex, there is increased hair follicle inflammation and decreased type 2 cytokines, mirroring the findings in mice. The study highlights the importance of ILC2s and IL-13 in maintaining skin integrity and preventing pathological mite infestation.